Sling construction and method of making same



B. c. BLACK 3,317,233 SLING CONSTRUCTION AND METHOD OF MAKING SAME May2, 1967 Filed April 20, 1965 INVENTOR. Born CI BLACK A TTOPNEY 3,317,233SLING CONSTRUCTION AND METHOD OF MAKING SAME Boyd C. Black, Rte. 5,Newark, Ohio 43055 Filed Apr. 20, 1965, Ser. No. 449,453 8 Claims. (Cl.234-74) This invention is related to a new wire rope sling and themethod for making such sling and more particularly relates to a wirerope sling wherein a protective wearresistant traction and cushioningsheath is provided, permitting adaption of such rope structure to thelifting of machined parts as well as soft metal parts requiring specialcare in handling.

Wire rope slings usually are used for lifting and ban dlingof heavyapparatus and component parts ranging in the order of 15 pounds or more,and lend themselves especially to such handling because of their hightensile strengths, and correspondingly because of the wide range ofloads which they can safely accommodate. Such rope slings areconventionally made of steel wire filaments grouped into strands twistedabout a hemp core or wire to produce a composite having the strength ofthe steel wire, but having a give or yield imparted by the inclusion ofthe hemp core and the orientation of the Wire strands thereabout. Manyspecific instances arise in the handling of machined parts and softmetal parts where direct abrasive contact of metal of such a rope withmetal of the object to be handled dictates that other means lessabrasive to the object be used. Under such circumstances,

less abrasive hemp ropes are most frequently resorted to because oftheir softer, less damaging nature when made to conform to the object tobe lifted, in comparison to theharder, non-smooth surfaced wire ropeslings.

, Wire rope slings, however, are still much more desirable for thehandling of such objects because of their greater tensile strength andlonger life, as well as their less bulky and clumsy character in sizesof comparable strength.

. In view of theforegoing, it is an object of the present invention toprovide an improved wire rope sling which incorporates the softer,non-abrasive characteristics of natural and synthetic fiber ropeswithout deterring from the inherent advantages of the wire rope, andadditionally, providing other improvements in properties whichheretofore have not been available in slings made either of wire -orfiber ropes, and in such sense, making the improved structure anall-purpose sling flexibly adaptable to an even wider range of uses thanhave been possible withboth wire and fiber rope slings taken as a group.It is another object of the present invention to provide an improvedwire rope structure having greater conformability to objects carried,and while enabling such conformity, still having anon-abrasive characterwith practically no tendency toward marring of the objects, regardlessofthe greater intimacy of contact established therewith.

It is another object of the invention to provide a wire rope slingstructure which has the effect of a greater yield with objects carriedto establish an improved conformability, while yet actually notmodifying the yield characteristic of the wire rope or cable itself.

It is still another objectof the invention to'provide awire slingstructure wherein the splices for the loops formed therein are protectedagainst damage from crushing and abrasion, thereby prolonging theeffective life of the sling.

A sling meeting the above objectives canbe produced according to thepresent invention by combination of a grease and oil resistant tubularcovering having a wearresistant exterior with a wire rope slingincorporating United States Patent 3,317,233 Patented May 2, 1967 a typewherein at least the interior which makes contact with the cable is bothoil and grease resistant, as Well as adaptable to a sliding action overthe surface of the strands of the rope, while the exterior is primarilytough and wear-resistant as well as of cushionable character, having ahigh coefiicient of friction, and yet being sufiiciently yieldable toprovide a desired degree of conformability. A hose found successful inproviding such characteristics is one available on the market having aninterior of neoprene and an exterior of rubber preferably reinforcedwith cord for greater ruggedness and limited extensibility beyond itsnormal length. Although a hose made of the neoprene and rubber is foundhighly successful, hoses fully of neoprene or other synthetic resins orcomposites thereof for many specific applications will, also, be founddesirable for such sling, structures. All neoprene hoses have theadditional feature in that the exterior as well as the interior is oiland grease resistant,

which in many instances is highly desirable because of vention, besideits high strength, yielding, traction gripping, and non-abrasive actionlies in the protection the covering oifer-s the wire rope itself, and inparticular, the spliced zones of the sling which are otherwise mostsubject to damage in the rough handling of such slings.

Other objects and features which I believe to be characteristic of myinvention are set forth with particularity in the appended claims. Myinvention, however, both in organization and manner of construction,together with further objects and advantages thereof may be bestunderstood by reference to the following description taken in connectionwith the accompanying drawing in which:

FIGURE 1 is illustrative of the general manner in Which a slingconstructed according to the present invention might be used to liftmachined parts;

FIGURE 2 shows the sling construction of the present invention in itsfully extended form;

g the sling casing;

FIGURE 4 is a cross-sectional view of the sling con 'struction of FIGURE3 as taken on line 3-3;

FIGURE 5 illustrates an arrangement of equipment and tools for making asling construction according to the principles of the present invention;

FIGURE 6 illustrates the arrangement of FIGURE 5 during the step offorming a concealed end loop in the sling construction.

Turning to the drawings in detail, FIGURE 1 shows a sling10 constructedaccording to the principles of the present invention supporting a metalhydro-propeller having machined surfaces and made of soft metal aboutwhich the sling must be wrapped to permit safe carriage thereof, such asby crane on the hook 12 of which the sling loops are held. In manyinstances, the sling is required to be wrapped about the machine partsto be lifted, as shown, by looping it in intimate contact with themachined surfaces of the parts. Under these circumstances, slippage of aconventional wire rope sling over the surfaces would likely damage thesurfaces, and after many such instances would, also, wear the slingitself.

According to the present invention, however, a traction-coveringmaterial such as of a hose 30 is provided over the major length of thesling to offer a traction surface for materials lifted thereby, as wellas to protect the wire rope and splices of the construction. The finalconstruction of the sling is illustrated in FIGURE 2, showing the hose30 extending over the full length of the wire rope between the end loopsor eyes 21 and 22.

FIGURES 3 and 4 illustrate more clearly actual construction details ofthe sling and show the hose construction and its manner of associationwith the wire rope in the zone of the splice forming the loop in one endof the sling. The hose 30 has an external layer 31 of rubber whichextends for a substantial distance through the thickness thereof and isreinforced by material such as rayon or nylon cord 32, while theinterior of the hose is lined with neoprene 33. The hose is selectedwith an interior diameter slightly larger than the diameter of the rope20 so that a gap exists between the rope exterior and the hose interiorto allow freedom of movement for the rope within the space provided.

The loop or eye 21 of the wire rope is formed by a splice 29 in a zone Swhere the end of the wire rope is, in a sense, folded back on itself toprovide a loop of the size desired. The splice is an in-laid loopsometimes called a buried-end or Concealed-end splice. A loop splice ofthis type is used because of its adaptability to providing a taper fromthe base of the loop over a distance of the rope sufiicient to allow awedging of the hose 30 over the splice. The ends of the strands of therope in such a splice are laid inside of the rope in the splice zone andreplace the core of the rope in this zone, thereby preventing cutting ofthe inside of the covering by providing ends. A well constructed spliceof this type is practically impossible to break loose and no wrapping ofseizings thereabout is necessary to maintain the splice, and especiallyis this so in the construction of the present invention since the hosecovering offers protection for the splice. For example, when slings areused to handle bundles of steel products such as pipe, sheet, or stripstock, it is customary, after placing the bundle, to pull the slings outfrom under it. When the slings are made with ordinary spliced loopswrapped with seizing strand, it is only a short time before the servingis pulled off. The tucked ends of the strand are then exposed. Thesecatch on the edges of the bundle and wires are turned up presenting ahazard to the workmen handling the slings. The hose covering, in thepresent instance, however, protects the splice against such occurrenceand, also, provides a hand grip for workmen with a minimum of hazard totheir becoming subjected to the abrasive and cutting action of strandends.

Beside the hose interior diameter being selected for provision of aclearance space for the rope over the major length of the sling, it is,also, selected to permit wedging of the end of the hose on at least aportion of the spliced zone to prevent and end-to-end movement of thehose on the sling construction.

FIGURE 4 illustrates, respresentatively, the clearance between the outersurface of the rope 20 and the interior of the hose for the length ofthe sling outside of the spliced zones, while FIGURE 3 illustrates incross-section the wedging of the splice in the end of the hose 30. Withthis arrangement, the hose is allowed to freely conform to the contoursof the rope on being looped about objects to be lifted, while at thesame time preventing unnecessary movement of the hose along the lengthof rope which would otherwise result in excessive abrading of theinterior of the hose. The splice is tapered down from the base of theloop over the zone S down to the real diameter of the rope and ishammered out for smoothness so that there are no high spots in thesplice.

FIGURES 5 and 6 illustrate the manner in which the new sling is made.Preliminary to the steps illustrated in these figures, however, an eyeor loop 21 is first made in one end of a preselected length of wire rope20. The loop is formed with a concealed-end loop splice as indicatedabove, which is hammered and smoothed out so that there are no highspots in the splice zone. The hose 30 is then cut to length so that inunstressed condition, it Will reach from the base of the loop 21 to thebase of the loop to be formed. The cut length of hose is then slippedover the free end of the sling and moved to a position where it iswedged against the base of the loop 21. The end of the wire rope is thensecured in a cable gripping tool 23 supported by rope falls or otherpulling mechanisms suspended from a fixed position above. The free endof the hose on the unlooped end of the wire rope is then inserted in avase 26 with the hose end abutting the under side of a pair of jaws 28between which the wire rope 20 is passed up to the cable grip 23. Thevise jaws 28 are maintained sufficiently far apart to allow free passageof the rope upward therebetween but sufiiciently close together so thatupon the cable being drawn upward, the abutting end of the hose will notslip through the jaws. The rope falls 24 are then drawn up tightly,effecting a compressed distortion of the hose until a sufficient lengthof the rope 20 is provided above the end of the hose that a spliced loopof desired size can be formed above the hose end. When such a length isprovided, the rope falls are securely locked so that no slippage willoccur and a cable clamp 27 is then placed around the outside of thehose, just below the jaws of the vise, which clamp is then tighteneduntil the hose end binds against the cable to prevent slippage of suchend along the length of the rope when the rope falls are released.

The assembly is then removed from its position in the vise shown inFIGURE 5 and is suspended in an inverted position, as illustrated inFIGURE 6, whereupon a loop 22 is spliced into the free end of the rope.

Upon completion, the second concealed-end splice 22 is, also, hammeredsmooth and the cable clamp 27 is removed to allow the hose to extenditself to its normal dimension. Manual assistance is then exercised towedge the end of the hose over the newly formed splice. In this respect,should difiiculty be experienced in drawing the end of the hose over thenewly formed splice, it has been found that the mild application of heatto the end of the hose, either by use of hot water poured directly overthe end, or by radiant heating of the end expands its diametersufficiently to permit relatively easy slipping of the hose to itswedged position. An ordinary radiant electrical heater is very usefuland successful in causing the necessary expansion of the hose end forwedging over the splice.

By way of example of an actual construction without intention that theinvention be so limited, a successful sling which was subjected toconditions of actual use with extremely favorable results wasconstructed of a inch cable and a inch four-ply rubber rayon-reinforcedair hose having a inch wall thickness and a neoprene inner liner. Thecable was selected to be approximately ,5 inch smaller in diameter thanthe inside diameter of the hose covering it and further was selected tohave a diameter such that a standard size hose could be used to therebyminimize the cost of materials. As indicated above, the neoprene linerof such a hose is more resistant than rubber to the grease and oil whichis always present in the cable and, therefore, lengthens the life of thesling considerably.

While I have shown a certain particular form of my invention, it will beunderstood that I do not wish to be limited thereto, since manymodifications may be made within the concepts of the invention. Forexample, the wire rope or cable as herein set forth can be a wire ropewith a hemp core or one with a metal core. Correspondingly, either steelor iron rope may be used and a variety of concealed-end splices might beused to present the preferred tapered exterior for wedging of the hoseends. Any desired length of sling can be made, and correspondingly, theeyes of the sling can be of any dimension required for specific needs.Furthermore, ferrule or sleeve-type splice clamps secured to the rope,can be utilized in abutting relation with the hose construction to wedgeand prevent sliding of the hose on the cable. In view of the foregoing,I therefore contemplate by the appended claims to cover all suchmodifications as fall within the true spirit and scope of my invention.

I claim as my invention:

1. A sling for lifting soft metal shaped articles and the likecomprising a length of wire rope, a loop formed at each end of saidsling by a splice of each end of said length back onto itself, each saidsplice being a concealed end splice gradually tapered down to thediameter of said rope over a portion of said rope extending from saidloop, and a hose covering said sling over the full length of said slingbetween said loops including said splices.

2. A sling for lifting machine parts and the like comprising a length ofwire rope, a loop formed at each end of said sling by a splice of eachend of said rope back onto itself, each said splice being a concealedend splice tapered gradually downward to the diameter of said rope overa portion of said rope extending from said loop, and a hose covering thefull length of the rope and splices between said loops, said hose havingan inner diameter slightly larger than the diameter of said ropeproviding clearance space between said rope and hose interior for thelength thereof between said splices.

3. A sling for lifting machine parts and the like comprising a length ofwire rope, a loop formed at each end of said sling by a splice of eachend of said rope back onto itself, each said splice being a concealedend splice tapered gradually downward to the diameter of said rope overa portion of said rope extending from said loop, and a hose covering thefull length of the rope and splices between said loops, said hose havingan interior lining of oil resistant, yieldable and stretchable material.

4. A sling for lifting machine parts and the like comprising a length ofwire rope, a loop formed at each end of said sling by a splice of eachend of said rope back onto itself, each said splice being a concealedend splice tapered gradually downward to the diameter of said rope overa portion of said rope extending from said loop, and a hose covering thefull length of the rope and splices between said loops, said hose havingan interior lining of neoprene.

5. A sling for lifting machine parts and the like comprising a length ofwire rope, a loop formed at each end of said sling by a splice of eachend of said rope back onto itself, each said splice being a concealedend splice tapered gradually downward to the diameter of said rope overa portion of said rope extending from said loop, and a hose covering thefull length of the rope and splices between said loops, said hose havingan inner diameter slightly larger than the diameter of said ropeproviding clearance space between said rope and said hose interiorbetween said loops, said splices for at least a portion of their lengthimmediately adjacent said loop having a diameter dimension slightlygreater than the interior of said hose to wedge said hose betweensplices and thereby prevent end to end movement of said hose on saidsling.

6. A sling for lifting machine parts and the like comprising a length ofwire rope, a loop formed at each end of said sling by a splice of eachend of said rope back onto itself, each said splice being a concealedend splice tapered gradually downward to the diameter of said rope overa portion of said rope extending from said loop, and a hose covering thefull length of the rope and splices between said loops, said hose havingan interior lining of neoprene and an exterior casing of rubber, saidhose having an inner diameter slightly larger than the diameter of saidrope providing a clearance between said rope and said hose interiorbetween said loops, said loops for at least a portion of their lengthimmediately adjacent said loop having a diameter dimension slightlygreater than the interior of said hose to wedge said hose betweensplices and thereby prevent end to end movement of said hose on saidsling.

7. The method of making a composite sling structure of wire rope and ahose covering having an inner diameter slightly larger than said ropecomprising in sequence splicing a loop in one end of a length of wirerope, passing the opposite end of said rope through said hose to aposition of projection from said hose, compressing said hose along itslength to a distorted contracted condition suflicient to permit splicingof a loop in the other end of said rope, clamping said hose in tightsurrounding relation against said rope, splicing a loop in said otherend of the rope, and releasing the hose from its contracted conditionand extending it over the full length of said rope including the splicesfor said loops.

8. The method of claim 7 wherein the released hose is heated tofacilitate its being forcefully extended over the full length of saidsling and both of said splices.

References Cited by the Examiner UNITED STATES PATENTS 2,454,417 11/1948Zerr 57142 2,491,256 12/1949 Engelke 5723 2,558,553 6/1951 Hansen et al.57-159 X 2,602,233 7/1952 Irving 57-153 3,018,319 1/1962 Quayle.

3,067,570 12/1962 Nischan 57-159 X M. HENSON WOOD, JR., PrimaryExaminer. I. N. ERLICH, Assistant Examiner.

1. A SLING FOR LIFTING SOFT METAL SHAPED ARTICLES AND THE LIKECOMPRISING A LENGTH OF WIRE ROPE, A LOOP FORMED AT EACH END OF SAIDSLING BY A SPLICE OF EACH END OF SAID LENGTH BACK ONTO ITSELF, EACH SAIDSPLICE BEING A CONCEALED END SPLICE GRADUALLY TAPERED DOWN TO THEDIAMETER OF SAID ROPE OVER A PORTION OF SAID ROPE EXTENDING FROM SAIDLOOP, AND A HOSE COVERING SAID SLING OVER THE FULL LENGTH OF SAID SLINGBETWEEN SAID LOOPS INCLUDING SAID SPLICES.